Oil circulating means for pistons and connecting rods



De 21. 1948 K. v. ANDERSON OIL CIRCULATING MEANS FOP!` PISTONS AND CONNECTING RODS Filed Sept. 18, 1946 2 Sheets-Sheet 1 FGUGL FiG.2

Dec. 2l, 1948.

Filed Sept. 18, 1946 K. V. ANDERSON OIL CIRCULATINQ MEANS FOR PISTONS AND CONNECTING RODS 2 Shoots-Shut 2 Mornago j Patented Dec. 21, 1948 OIL CIRCULATING MEANS FOR PISTONS AND CONNECTING RODS Karl V. Anderson, Milwaukee, Wis., asslgnor to Nordberg Manufacturing Co.,

a corporation of Wisconsin Milwaukee, Wis.,

Application September 18, 1946, Serial No. 697,775

4 Claims. l

This invention relates to means for cooling the pistons of internal combustion engines by means of oil which lubricates the crank pin and wrist pin bearings.

It is known practice to cool the piston by oil fed under pressure through the connecting rod. In such case the usual practicev has been to discharge the oil from the piston through a port that allowed the oil to fall freely to the crank case, an arrangement which is entirely'workable with vertical engines. It is not satisfactory with engines having inclined or horizontal cylinders (for example), because the hot oil leaving the plston'should at least be cooled before it reaches any part requiring lubrication.

According to the present invention the oil is fed through the crank and connecting rod to they piston, feeding the crank pin and wrist, pin bearings on its way. From the piston the oil follows a different path through the connecting rod so arranged that when the oil passes the wrist pin bearing differential pressures will resistA entrance of hot oil into the bearing. The hot oil discharges from the crank end pin without reaching its bearings. From the crank end pin the oil discharges into a collector that leads it to a "con-l ditioning device which may merely cool the oil, though fl'tering and centrifuging steps are obvious possibilities. The invention is not concerned with the treatment to be used to improve the properties of the oil.

The invention is of generalJapplicability, but

'j merely as a basis of explanation, will be described as embodied in a multicylinder radial engine havingI a vertical crank shaft, and a crank ring which revolves with the crank but does not rotate. This particular crank arrangement is described and claimed in my copending applicatiomserial No. 692,982, filed August 26, 1946. To an extent it complicates the problem of transmitting the oil to the pistons and hence offers a favorabie opportunity to indicate the adaptability of the invention and illustrate features developed for the particular exigencies presented by the design.

The invention will now be described by reference to the accompanying drawing, in which:

Fig. 1 is a vertical axial section of enough of the engine to show the crank shaft and crank, a main bearing, the non-rotating crank ring and one complete piston-connecting-rod unit.

Fig. 2 is a view of a piston-connecting-rod unit drawn on a larger scale than Fig. l and chiefly in axial section, to show the porting.

' Fig. 3 is a section on the line. 3-3 of Fig. 2.

' Figs. 4 to 7, inclusive, are respectively fragmentary sections on the lines 4-4, 9 6, 8-9 and 1--1 of Fig. 2. L

A portion of the engine frame appears at II and supports a main bearing I2 in which one journal I3 of crank shaft I4 turns. Shaft I4 extends downward to connect with driven apparatus, not shown.

Shaft I4 carries a crank pin I5 between counterweighted throws I3 and I1, and this turns in a non-rotating revolving ring made up of a sleeve I8 and two spaced flanges I9. There is the usual bearing bushing 2|. The teeth 22 in the upper ilange I9 and the two pinions 23, 24 are part of a planetary gear train used to inhibit rotation of the ring while permitting it to revolve. The invention is not directly concerned with this detail.

Rotating in bearing bushings 25 in the flanges I9 are hollow tubular pins 29, which are clamped in the crank ends of' connecting rods 21. There is one for each cylinder, and the engine here illustrated has eleven radially arranged cylinders I28, only one of which appears in Fig. 1. The way in which pins 25 are mounted forms the subject of my copending patent application, above identitled.

Each cylinder 23 has a piston 29 with wrist pin' 3| fixed therein by retainer heads 32. Each rod 21 has a bearing bushing 33 which works on the corresponding wrist pin,

The general organization of the engine being understood, the oil paths can now be traced.

A lubricating pump (not shown) delivers oil under pressure to conduit-34 which leads to port 35 in main bearing I2. This registers with groove i 33 in journal I3, from which a passage 3l, 38, 39 leads to radial ports 4I in crank pin l5. These communicate through grooves 42 with radial ports 43 in the flanges I9 of the revolving ring.

All oil passages so far described conform to known practice and are shown in Fig. 1. Refer now to Figs. 2-7 and particularly Figs. 2 and 3. The ports 43 enter annular grooves 44 (see Fig. 4) which are formed in flanges I9 and encircle bearing bushings 25.- They lead to radial ports 45, 'through the bushing. These feed grooves 46 in bushing 25 communicate with four drilled ports 48 in pin 23 by way of radial passages 41 (see Fig, 4). Ports'49"-(see Fig. 3) lead to passage 49 which extends the length of rod 21. branches at 5I and so leads to two grooves 52 which encirclel the-wrist pin bushing 33 (see Figs. 2 and 5).

As best shown in Fig. 5. the flow is from grooves 52 through radial ports 53 to groove 54 cut in bushing 33 and thence by radial ports 65 in the wrist pin 3l to six longitudinal ports 58 in the Y El and groove 58 (see Figs. 2 and 6) with the entrance end of the ton 29 (see Fig. 2)

The e'xit end of coil E8 (see Fig. 7) is connected by groove 6l and radial ports 62 lwith longitudinal passages, six in number, interspersed between ports 58. The passages 53 (see Fig. 3) have one set oi radial ports 64 which lead to annular groove 8B out in bushing 33 and thence through ports 66 also in bearing bushing 33 to annular groove 61 which is formed in rod 27 and leads to longitudinal passage 8B (see Fig. 3) in rod 21. This leads through four radial ports S9 through pin 26 to the bore of that pin. Refer now to Fig. 1. Oil discharging from the bore of the various pins 26 is thrown out against baille Il and drains through port 12, chamber 13 and port 'il to the conduit 'l5 which leads to an cooling coil '59 cast in the pisoil-reconditioning means of any suitable type (not shown).

Thus. hot oil discharging from the pistons ows to the conditioner without reaching any lubricated part. The nearest approach to contact is at groove 55, but back pressure in groove 65 is slightly lower than pressure of the cool oil in adjacent grooves 54, so that the cool oil will seep across and resist entrance of the hot cil into the wrist pin bearing. There is some short circuit now. at this point and the action is desirable because whatever oil tends to enter is cool and acts to sweep out hot oil.

The arrangement vaiords adequate cylinder cooling with strict control of the hot oil. It requires no accessories such as trombone connections, which cannot be used successfully with high speed engines. p

As stated, the described embodiment is illustrative of the invention, which is applicable to other types of engine and would of course be modiiied to suit.

What is claimed is:

1. The combination with a piston, connecting rod and crank mechanism of a connection for supplying oil under pressure; a cooling passage in the piston; communicating passages in the crank and connecting rod fed by said supply connection, and serving to conduct oil under pressure to the entrance end of the passage in the piston; a distinct passage in the connecting rod leading from the exit end of said passage in the piston to a discharge near the crank; and oil-collecting means having a portion encircling the orbit of the crank and arranged to intercept discharging oil.'

nueces l 2. The combination oi a crank having an oil passage; a connection for supplying oil under pressure thereto; a revolving ring journaled in the crank and having an oil passage communieating with the passage in the crank; at least one piston and connecting rod unit in which the rod has a wrist pin bearing connection with the piston and a Journal pin bearing connection with the ring; means for lubricating said bearings and cooling the piston comprising a passage which leads from the passage in the ring. through the rod in communication with both pin bearings, thence through the piston and back. through the rod to an outlet located substantially at the journal pin; and oil-collecting means having a portion encircling the orbit of the ring and arranged to intercept discharging oil.

3. The combination defined in claim 2 in which the journal pin is vtubular and ilxed in the rod, and the return passage discharges into the bore of the pin, escapes freely from the end thereof and thus by-passes the journal pin bearing.

4. The combination of a piston having an oil cooling passage; a connecting r'od having lan oil supply passage and an oil return passage; a wrist pin forming a connecting bearing between the piston and connecting rod, said pin having passages which connect the oil supply and oil return passages in the rod with opposite ends of the oil cooling passage in the piston and which respectively vcommunicate at spaced points with the wrist pin bearing; and connections for supplying oil under pressure to said supply passage, the parts being so proportioned and arranged Y,that owing oil is subjected to a substantial pressure drop as it cws through the piston passage, whereby pressure developed in the wrist pin bearing by oil from the .supply passage will resist entrance into the bearing of oil from the return passage.

KARL V. ANDERSONe REFERENCES errno The following 'references are of record in the nie of this patent:

UNITED STATES PATENTS Name Date Church Nov. 1, 1988 sonaron Pam'Nfrs Number 

